From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f49.google.com (mail-wg0-f49.google.com [74.125.82.49]) by kanga.kvack.org (Postfix) with ESMTP id 228C16B0031 for ; Mon, 7 Apr 2014 11:10:51 -0400 (EDT) Received: by mail-wg0-f49.google.com with SMTP id a1so7090440wgh.32 for ; Mon, 07 Apr 2014 08:10:50 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id bw16si5259030wib.115.2014.04.07.08.10.49 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 07 Apr 2014 08:10:49 -0700 (PDT) From: Mel Gorman Subject: [RFC PATCH 0/3] Use an alternative to _PAGE_PROTNONE for _PAGE_NUMA Date: Mon, 7 Apr 2014 16:10:40 +0100 Message-Id: <1396883443-11696-1-git-send-email-mgorman@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds Cc: Cyrill Gorcunov , Mel Gorman , Peter Anvin , Ingo Molnar , Steven Noonan , Rik van Riel , David Vrabel , Andrew Morton , Peter Zijlstra , Andrea Arcangeli , Linux-MM , Linux-X86 , LKML Aliasing _PAGE_NUMA and _PAGE_PROTNONE had some convenient properties but it ultimately gave Xen a headache and pisses almost everybody off that looks closely at it. Two discussions on "why this makes sense" is one discussion too many so rather than having a third there is this series. Conceptually it's simple -- use an unused physical address bit for _PAGE_NUMA and make it a 64-bit only feature on x86. This had been avoided before because if the physical address space expands we are back to square one but lets worry about that when it happens unless the x86 maintainers or hardware people warn us that we're about to run headlong into a wall. Testing was minimal -- short lived JVM and autonumabench tests that trigger the relevant paths for NUMA balancing. Functionally it did not die miserably. Performance looks as expected with no major changes. arch/x86/Kconfig | 2 +- arch/x86/include/asm/pgtable.h | 8 +++---- arch/x86/include/asm/pgtable_types.h | 44 ++++++++++++++++++++---------------- mm/memory.c | 12 ---------- 4 files changed, 29 insertions(+), 37 deletions(-) -- 1.8.4.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org